Figure 4
The refracting ISW model.
(a) 3D sketch of the KdV model and the simulated topography used for equation (3). The yellow surface represents an ISW of amplitude η, while h1 and h2 are the upper (TSW) and bottom (LIW) layer thicknesses, respectively. Note that h2 varies along the y-axis due to sea floor topography (brown surface). The dashed line indicates the unperturbed interface between the two layers. (b) Results of equation (3) for different initial angle between the ISW vector and the bathymetry in the deepest part of the sand-wave field (map generated by SURFER 10.2 http://www.goldensoftware.com/products/surfer). Yellow curve: h1 = 149 m, H = 151 m, d = 8 × 10−2; Green curve: h1 = 149 m, H = 151 m, d = 5 × 10−2; Red curve: h1 = 100 m, H = 200 m, d = 5 × 10−2. All curves are obtained with θ0 = Π/2.5 and g’ = 8 × 10−2 m s−2. The three curves show that the ISW refraction increases by increasing the topographic slope (d) and/or by decreasing the initial bottom layer thickness H (See Supplementary Information for a full description of Equation 3 solution). The yellow curve orthogonally runs best along the sand waves since h1, H, and d values are very close to the real ones.
